Rotary pump



Dec. 24, 1935:,` A, G, EERGSTRQM 2,25,084

ROTARY PUMP Filed March 28, 1935 Kfz/2224252? /4 /5 www@ Mgg llllnvllu v lIIIII l f .1, lllllllllll mmm-el;

Patented Dec. 24, 1935 UNITED STATES PATENT OFFICE 5 Claims.

The pump of the present invention is designed for various uses in which it is desired to maintain uniformity in the flow of water or other liquid at a desired head or under a given pressure, and is particularly adapted for use as a booster pump in accelerating the oW of water or other liquid diverted from a main channel, or for maintaining a constant flow from a drinking fountain or the like, without surging or tendency to momentarily reverse the water flow.

The pump is peculiarly adapted for use in small sizes and Where a moderate floW is desired under a given head, although the invention is not limited exclusively to such use.

In the form shown, the pump is associated with a motor as a unit adapted for quick and easy attachment to the piping of a heating system or the like for the purpose cf operating as a booster pump, although it will be understood that the particular method of mounting shown serves merely for purposes of illustration and that the invention is not limited to this particular method of mounting the operating elements of the pump.

Further objects and details will appear from the description of the invention in conjunction with the accompanying drawing, wherein,-

Figure 1 is a sectional plan View of the pump associated With a motor; and

Fig, 2 is an elevation partly in section taken on line 2-2 of Fig. 1.

The'puinp comprises a casing which, as shown, may be in the form of a casting having a body of cross-shaped conguration comprising an outer leg I0, a shorter leg II, and laterally `projecting arms I2 and I3. The casing is cored to afford a cylindrical pump chamber I4 which merges into a tapped discharge port I5 of lesser diameter, which receives the end of a discharge pipe I B. l

The chamber at its inner end merges into a cross bore comprising sections II and I8 formed respectively in the arms I2 and I3 of the casing. The cross bore is of lesser diameter than the pump chamber which thus intersects the cross bore, affording curving top and bottom walls I9 and respectively, which constitute continuations of the wall of the pump chamber and of equal curvature therewith. This enlargement at the intersection of the longitudinal and cross bores constitutes what may be ,termed a water inlet chamber.

The short leg I I of the casing is provided with a tapped opening 2| which receives a threaded plug 22 having a hexagonal outer head 23 and terminating at its opposite end in an inwardly (Cl. 10S- 89) projecting sleeve 24 cored to aiford a pump inlet chamber 25 which communicates with the water inlet chamber through a port 26 formed in the bottom Wall of the sleeve. The exterior of the sleeve is of lesser diameter than the Water inlet 5 chamber which thus affords a channel around the sleeve, which, however, is separated from the pump chamber by the provision of a marginal flanged lip 2'? on the inner end of the sleeve, the rim of which lip ts snugly against 10 the Wall of the pump chamber, thus sealing the pump chamber against the admission of water save through the water inlet chamber and through the pump inlet chamber.

The Water is admitted to the water inlet cha-mber through a pipe 28 which is tapped into the arm I3 of the casting, the opposite arm being provided with a threaded closing plug 29. It is obvious, however, that either of the arms might be used for the reception of the Water inlet pipe and the opposite arm plug to prevent leakage.

Within they pump chamber is located a spiral blade 30 mounted on the inner end of a pump shaft 3l. The blade constitutes a convolute screw pump element and is of proper diameter to bring its rim closely adjacent to the cylindrical Wall of the pump chamber, with the inner end of the convolute blade lying closely adjacent to or in contact with the face of the lip 2'I, which as shown is preferably beveled to maintain a close relationship to the inner end of the blade.

The blade, as shown throughout its extent from end to end, surrounds the end of the shaft through a complete turn or circle of 360, which brings the inner end of the convolute substantially into longitudinal register with the outer end on the same side of the shaft.

'I'he pump shaft 3| passes through a gland 32 and is connected by a coupling 33 with a motor shaft 34 driven by a motor 35, which as shown is mounted within an apron 36 which is cast onto the pump casing and extends rearwardly therefrom, a rib 31 being provided below the pump casing to reinforce the connection.

In operation, the pump shaft is driven at the desired speed which rotates the screw element within the pump chamber, and by reason of the close fitting between the convolute blade and the lip 21 and the Wall of the pump chamber causes the water or other liquid to be acted upon in a solid stream by the pump, so that there will be no possibility for the bypassing of the Water around the blade, thus preventing the churning up or breaking of the water column which might occur if a portion thereof were diverted past the 55 CII j Cil convolute blade Without actually being brought into impingement therewith.

This pumping action is further assisted by the conguration of the Water inlet passages which are so formed as to compel the travel ci the Water through a somewhat circuitous path before it is admitted directed against the blade of the pump, the arrangement being one which prevents the entrance of any Water into the pump chamber save that admitted directly against the pump blade and into the eye of the pump.

Furthermore, the arrangement of the water passages constitutes a seal or check against the back flow or seepage of Water, since the entire column of Water will be subjected to and supported against the surface o the rotating screw pump element, so that there Will be no tendency for the column to break or disintegrate or become churned by the action of the pump element so long as the pump is operating Within the maximum limits of its capacity.

By constructing the pump in the manner described, it is possible to maintain the Water flow uniform at the desired rate under a given head and without the employment of check valves or the like, since the pump, acting directly upon an unbroken column of water, Will advance the same evenly and uniformly and Without escape or back flow due to churning or failure of the pump element to act upon the column as a Whole.

I claim:

1. In a pump of the class described, the combination of a casing aioiding a cylindrical pump chamber, a convolute pump element carried by a'shaft rotatably mounted Within the pump charnber and having a continuous blade Whose rim lies in closely adjacent relation to the Wall of the chamber throughout at least a complete turn of the convolute, and a pump inlet chamber for admitting liquid centrally of the pump element, the discharge end of the pump inlet chamber being coniigured to aord a rim surface closely contiguous to the inner end of the convolute pump element, the pump inlet chamber being provided with a laterally disposed port and a Water inlet chamberrsurrounding the pump inlet chamber and provided with a Water inlet pipe discharging inwardly to the water inlet chamber at a point out of register with the pump inlet chamber port to provide for a circuitous inflow of Water.

2. In a pump of the class described, the combination of a casing affording a cylindrical pump chamber, a convolute pump element carried by a shaft rotatably mounted Within the pump chamber and having a continuous blade Whose rim lies in'closely adjacent relation to the Wall of the Vchamber throughout substantially a complete turn of the convolute, and a pump inlet chamber hav- ,ing a discharge opening of lesser diameter than the pump chamber and centrally disposed with relation to the axis of the pump for admitting liquid centrally of the pump element, the discharge end of the pump inlet chamber being con-- figured to afford a rim surface closely contiguous to the inner end of the convolute pump element, the pump inlet chamber being provided with a laterally disposed inlet port and a Water inlet chamber surrounding at least a portion of the ,pump inlet chamber and provided with a water inlet pipe discharging inwardly to the water inlet chamber at a point out of register with the pump inlet chamber port to provide for a circuitous inflow of Water.

3. In a pump of the class described, the combination of a casing aiording a cylindrical pump chamber, a convolute pump element carried by a shaft rotatably mounted Within the pump chamber and having a blade whose rim lies in closely adjacent relation to the wall of the chamber throughout at least a complete turn of the convolute, and a pump inlet chamber of lesser diameter than the pump chamber and centrally disposed with relation to the axis of the pump for admitting liquid centrally of the pump element, the discharge end of the pump inlet chamber being coniigured to afford a rim surface closely contiguous to the inner end of the convolute pump element, the pump inlet chamber being provided With a laterally disposed inlet port and a Water inlet chamber surrounding the pump inlet chamber and provided with a Water inlet pipe discharging inwardly to the Water inlet chamber at a point out of register with the pump inlet chamber port to provide for a circuitous inflow of 20 Water.

4. In a pump of the class described, the combination of a casing provided on its interior with a longitudinally disposed cylindrical pump chamber and a Water inlet chamber adjacent there- 25 to, a sleeve extending through the Water inlet chamber and ci" lesser diameter than the chamber to afford a surrounding Water inlet passage, the sleeve being bored on its interior to afford a pump inlet chamber having an inlet port 30 through the Wall of the sleeve for the admission of Water, the sleeve being provided at its inner end vvith a ilanged lip having its rim in closely adjacent relation to the inner end of the Wall of the pump chamber, a pump shaft entered through 35 the sleeve and having its inner end projecting Within the pump chamber, a convolute pump blade surrounding the shaft throughout at least one complete turn and having its rim in closely adjacent relation to the cylindrical Wall of the 0 pump chamber and having the inner end. of the convolute blade in closely adjacent relation to the langed lip on the sleeve, and Water inlet and discharge pipes communicating respectively with the inlet chamber and the pump chamber.

5. In a pump of the class described, the combination of a casing provided on its interior with a longitudinally disposed cylindrical pump chamber and a Water inlet chamber adjacent thereto,

a sleeve extending through the Water inletchamber and of lesser diameter than the chamber to afford a surrounding water inlet passage, the sleeve being bored on its interior to afford a pump inlet chamber having an inlet port through the Wall of the sleeve for the admission of Water, the sleeve being provided at its inner end with a flanged lip having its rim in closely adjacent relation to the inner end of the Wall of the pump chamber, a pump shaft entered through the sleeve and having its inner end projecting Within the pump chamber, a convolute pump blade surrounding the shaft throughout at least one cornplete turn and having its rim in closely adjacent relation to the cylindrical wall of the pump cham ber and having the inner end of the convolute blade in closely adjacent relation to the flanged lip on the sleeve, and Water inlet and discharge pipes communicating respectively With the inlet chamber and the pump chamber, the water inlet pipe being out of register with the inlet port through the sleeve to provide for a circuitous inflow of water.

ADOLPH G. BERGSTROM. 

